title: Binding of the repressor complex REST-mSIN3b by small molecules restores neuronal gene transcription in Huntington's disease models.
abstract: Transcriptional dysregulation is a hallmark of Huntington's disease (HD) and one cause of this dysregulation is enhanced activity of the REST-mSIN3a-mSIN3b-CoREST-HDAC repressor complex, which silences transcription through REST binding to the RE1/NRSE silencer. Normally, huntingtin (HTT) prevents this binding, allowing expressing of REST target genes. Here, we aimed to identify HTT mimetics that disrupt REST complex formation in HD. From a structure-based virtual screening of 7 million molecules, we selected 94 compounds predicted to interfere with REST complex formation by targeting the PAH1 domain of mSIN3b. Primary screening using DiaNRSELuc8 cells revealed two classes of compounds causing a greater than two-fold increase in luciferase. In particular, quinolone-like compound 91 (C91) at a non-toxic nanomolar concentration reduced mSIN3b nuclear entry and occupancy at the RE1/NRSE within the Bdnf locus, and restored brain-derived neurotrophic factor (BDNF) protein levels in HD cells. The mRNA levels of other RE1/NRSE-regulated genes were similarly increased while non-REST-regulated genes were unaffected. C91 stimulated REST-regulated gene expression in HTT-knockdown Zebrafish and increased BDNF mRNA in the presence of mutant HTT. Thus, a combination of virtual screening and biological approaches can lead to compounds reducing REST complex formation, which may be useful in HD and in other pathological conditions.
authors.affiliation: Department of BioSciences, Università degli Studi di Milano, Milano, Italy; Center for Stem Cell Research, Università degli Studi di Milano, Milano, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Conforti
authors.forename: Chiara
authors.initials: C
authors.lastname: Zuccato
authors.forename: Germano
authors.initials: G
authors.lastname: Gaudenzi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ieraci
authors.forename: Stefano
authors.initials: S
authors.lastname: Camnasio
authors.forename: Noel J
authors.initials: NJ
authors.lastname: Buckley
authors.forename: Cesare
authors.initials: C
authors.lastname: Mutti
authors.forename: Franco
authors.initials: F
authors.lastname: Cotelli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Contini
authors.forename: Elena
authors.initials: E
authors.lastname: Cattaneo
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D056970:Co-Repressor Proteins; D004625:Embryo, Nonmammalian; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D000071058:Huntingtin Protein; D006816:Huntington Disease / Q000235:genetics* / Q000378:metabolism*; D007150:Immunohistochemistry; D008156:Luciferases / Q000378:metabolism; D008845:Microinjections; D008958:Models, Molecular; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000008:administration & dosage / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics / Q000502:physiology*; D014162:Transfection; D015027:Zebrafish
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D056970:Co-Repressor Proteins; C086055:HTT protein, human; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins; C121019:RCOR1 protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012097:Repressor Proteins; C492042:SIN3B protein, human; D008156:Luciferases
keywords: BDNF; Huntington's disease (HD); REST/NRSF; protein-protein interaction; virtual drug screening